The present invention relates to the art of warming devices for warming golf balls. More particularly, the present invention relates to the art of portable warming devices for warming modern golf balls to improve performance characteristics during play.
The modern golf ball has undergone significant changes from its humble beginnings in the sixteenth century. In 1550, golf balls were made from wood and could travel a distance of up to 150 yards when struck. In the 1750s golf balls were made from leather, such as bull or horse hide, and stuffed with feathers. However, by 1850, golf balls were made in a one-piece construction from a rubbery substance known as "gutta percha."
By 1898, Coburn Haskell invented a "wound" golf ball which included a plurality of rubber strands wrapped around an interior core. By this time, golf balls were routinely being hit upwards of 200 yards. In 1921, the USGA (United States Golf Association) set a number of manufacturing criteria for golf balls including the requirement that no ball can weigh more than 1.62 ounces or be smaller than 1.62 inches in diameter.
Throughout the earlier part of this century, the USGA has frequently changed their criteria for golf ball construction and in 1942 adopted the initial velocity test to constrain the "liveliness" of golf balls to 250 feet per second, with a two percent tolerance. Since 1951, the USGA and the R&A (the Royal and Ancient Golf Club of St. Andrews, Scotland) have agreed upon golf standards including golf ball and golf club dimensions. In the 1950s most golf balls were made from a "three-piece" construction including an inner core (first piece), a plurality of windings (second piece), and a rubbery outer layer (third piece).
By the 1960s, "two-piece" golf balls became increasingly popular due to increased distance from 5-iron club lofts. However, the two-piece golf balls still met the USGA criteria for traveling a set distance at driver lofts.
Today, the USGA has adopted an indoor test for golf balls which simulates outdoor performance by propelling golf balls into a screen which is 70 feet from a launch position. Ball construction has likewise changed, and today golf balls are manufactured in the two-piece and three-piece, i.e. "wound" variety.
Three-piece golf balls, generally considered as superior by better golfers, have a liquid center or a solid center made from an elastic material such as polybutadiene. Three-piece golf balls are usually wound with a rubbery thread and covered with a form of rubber, i.e. polyisoprene. The most popular form of rubber for the outer coating of three-piece golf balls is "balata," which denotes the trans isomer form of polyisoprene. The cover material for golf balls generally has a hardness of 50 to 75 Shore D, and an icosahedron or modified cuboctahedron dimple pattern which generally covers upwards of 80% of the outer surface area. Often a plurality of different dimple types are simultaneously disposed on a golf ball surface to form the dimple pattern.
Modern two-piece golf balls generally have a tough outer coating of "surlyn" or a "surlyn/lithium" composite. This composite is more resistant to cutting and deformation than a balata cover and exhibits improved performance when heated to well above normal ambient temperatures.
The heating of golf balls improves performance without harmful effects or deterioration of the ball. When sufficiently heated, a modern golf ball will generally travel farther and feel "softer" when hit with a golf club. This farther travel and more comfortable feel allows for more enjoyable play, especially during cool weather.
The generally accepted rules of golf, i.e. the "Rules," are promulgated by the United States Golf Association and are incorporated herein by reference. The Rules specifically disallow the use of artificial equipment during specified play. More particularly, Rule 14-3 provides in pertinent part that " . . . during a stipulated round the player shall not use any artificial device or unusual equipment . . . which might assist him or her! in making a stroke or . . . play."
Ever since golf balls have been manufactured from elastomer materials, a number of heat sources have been employed to warm golf balls and thereby enhance play. In fact, Walter Darden Hampton recognized that a portable golf ball heater may increase drive distance as early as 1942. Hampton, in U.S. Pat. No. 2,272,340, sets forth a chemically active heat pack which transmits heat to four golf balls disposed within a heat chamber. Hampton allows unidirectional upward movement of four golf balls within the heat chamber by way of insertion through cross-slit flaps. The cross-slit flaps are stiff and do not open under weight of the golf balls. However, undesirable ambient air enters the heat chamber during insertion and removal of the golf balls, and while the balls are at rest. Moreover, the chemical heating element only partially surrounds the heat chamber and a non-heated side of the heat chamber is not insulated against heat loss. Thus, golf balls stored within the heat chamber become heated unevenly.
Cohen, in U.S. Pat. Nos. 4,144,002, 4,967,062 and 5,057,670 sets forth a golf ball heating device which generates heat by electrical resistance from an external source. Cohen includes a divider which restricts movement of ambient air into the ball chamber during removal of a golf ball. However, the electrical resistance elements are an artificial means of heating golf balls and require a source of power. Cohen requires connection to an inconvenient electrical outlet or the use of batteries which must continually be replaced. Thus, Cohen does not meet the need for a portable golf ball warming device which does not require a source of power.
A number of prior disclosures suggest the use of chemically reactive heating composites as an alternative to electrical heat. For example, Roth, U.S. Pat. No. 5,137,011 and Parrott, U.S. Pat. No. 5,460,160 each use chemically reactive, disposable heating composites to supply continuous heat for approximately 4 to 6 hours. However, an inherent drawback of such devices is a constant need to replace the chemical heat pack. Hendricks, U.S. Pat. No. 4,545,362 includes a non-disposable, chemically reactive heat pack. However, the chemical heat pack of Hendricks is still considered artificial heat. Moreover, chemically reactive heat packs afford a maximum temperature of 127.degree. Fahrenheit or less.
Many prior art devices require golf ball insertion and dispensing arrangements which are detrimental to the conservation of heat within a warming compartment. Such devices often sacrifice the economy of hand movement as well. For example, Parrott '011 discloses a staged warming pathway through which golf balls are unidirectionally moved from top to bottom, with a bottom ball captured in an insulated cap. The insulated cap is then removed to release a warmed golf ball. However, this configuration does not allow heated air to rise through the warming compartment and therefore subjects only the topmost, i.e. last inserted, ball to receive the highest temperatures within the device.
Furthermore, many prior devices set forth inconvenient means of ball insertion and removal. Often times, two separate removable end caps are provided which require the use of two hands for the separate actions of: top cap removal, ball insertion, top cap replacement, bottom cap removal, ball retrieval, and bottom cap replacement. Many prior devices also require a complex arrangement of different components which increase manufacturing and assembly costs.
Gravatt, U.S. Pat. No. 3,497,676 sets forth a golf ball warmer using a combination of solar energy and battery power. Gravatt provides a small and portable arrangement. However, when a cover/absorption plate assembly is opened to remove a golf ball, all of remaining balls are subjected to ambient air, thereby permitting considerable heat loss from the ball compartment. Moreover, additional ball compartments are necessary for storing multiple balls during an extended round of golf.
Schroth, U.S. Pat. No. 3,720,197 sets forth another solar design for a golf ball warmer. An absorber plate conducts solar heat energy to a golf ball compartment, but opens through a hinge which allows heated air to escape. While Schroth provides a D.C. battery backup system, the maximum temperature of the applied heat is limited to approximately 134.degree. Fahrenheit. Moreover, clam-shell type absorption plates as used by Schroth necessitate that only one side of the golf balls receive the maximum generated heat. Consequently, the clam-shell type of solar golf ball warmers fail to warm golf balls in a symmetrical manner so as to ensure even heating throughout.
In view of the above, a need exists for a golf ball warming device which is self-contained, and provides a sufficient quantity of warmed golf balls throughout an extended round of play without dependence upon any artificial source of heat energy.
A further need exists for a golf ball warming device which facilitates simple and economic hand movement when loading and dispensing golf balls, and maintains heat within a golf ball warming chamber while denying exposure of the warmed golf balls to ambient air until required.
An additional need exists for a golf ball warming device which is simple in design, portable, and provides for higher temperatures as required to impart greater benefits to a modern golf ball having a two-piece construction.